Field of the Invention
The present invention relates to an injection molding machine, and particularly to an injection molding machine including a plurality of injection units with respect to a single mold clamping mechanism.
Description of the Related Art
In an injection molding machine, materials of two or more colors or materials different from one another are used to perform injection molding in some cases. In such cases, two or more injection units are provided with respect to a single mold clamping device so that the injection units inject two or more types of resin into the die to produce molded articles.
Japanese Patent Application Laid-Open Nos. 10-58479, 2001-79877, and 2001-219456 disclose technologies about a molding method and an injection molding machine in which one mold clamping device is provided with respect to a plurality of injection units and the plurality of injection units are sequentially operated to mold a unitary molded article made of a plurality of materials. Among the patent documents described above, Japanese Patent Application Laid-Open No. 2001-79877 discloses a technology for performing sequence control in a predetermined order on independent motion of each of two injection molding machines provided for one mold clamping device.
Each of the patent documents described above discloses an injection molding machine that uses a plurality of injection units to mold a unitary molded article and an injection molding method using the injection molding machine but does not describe anything about how to handle malfunction of the injection molding machine. Therefore, when one of the plurality of injection units malfunctions, simply stopping the malfunctioning injection unit itself may still allow the other injection units to keep operating and molding an unintended molded article because the other injection units are not configured to execute an appropriate processing.